.flex {
  display: flex;
  justify-content: center;
}
.space {
  box-sizing: border-box;
  padding: 0 20px;
}
.drag {
  box-sizing: border-box;
  padding: 20px;
}
.link {
  transition: color 0.5s;
}
.link:hover {
  color: #1890ff;
}
.header {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
}
.header .mb-20 {
  margin-bottom: 20px;
}
.preview {
  max-width: 50px;
  max-height: 50px;
}
